WebSVN - Projects - Blame - Rev 1396 - /RC-Expander/branches/MX16s_9Ch

Rev	Author	Line No.	Line
1396	-	1	/*------------------------------------------------------------------------------
		2	Ident : main.c
		3	Project : MX16s 8->9 ppm channel expander
		4	Author : lakeroe
		5	Description : main module
		6	Copyright (c) : 12.2011 lakeroe
		7	Original code and idea : Jacques Wanders
		8	http://forum.mikrokopter.de/topic-4405.html
		9	http://forum.mikrokopter.de/topic-4556.html
		10	----------------------------------------------------------------------------
		11	Release : v1.0 initial release
		12	Date : 25-12-2011
		13	----------------------------------------------------------------------------
		14	The use of this project (hardware, software, binary files, sources and
		15	documentation) is only permittet for non-commercial use
		16	(directly or indirectly)
		17	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
		18	AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
		19	IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
		20	ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
		21	LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
		22	CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
		23	SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
		24	INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
		25	CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
		26	ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
		27	POSSIBILITY OF SUCH DAMAGE.
		28	------------------------------------------------------------------------------*/
		29
		30	#include <avr/io.h>
		31	#include <avr/interrupt.h>
		32	#include "main.h"
		33
		34	enum
		35	{
		36	stPPM_SYNC,
		37	stPPM_SYNC_WAIT,
		38	stPPM_CHANNEL_START,
		39	stPPM_CHANNEL_DATA,
		40	stPPM_CHANNEL_9_DATA,
		41	stPPM_FINISH_PULSE,
		42	stPPM_FRAME_END
		43	};
		44
		45	unsigned char channel_number = 0;
		46	unsigned char ppm_state = stPPM_SYNC;
		47
		48	// timer1_capture_interrupt (void)
		49	// Synchronise PPM frame and copy input events to PPM_OUT, start mixing Ch9 data when detect start pulse of Ch9
		50	ISR (TIM1_CAPT_vect)
		51	{
		52	cli (); // disable interrupts
		53	unsigned int data;
		54
		55	switch (ppm_state)
		56	{
		57	case stPPM_SYNC: // detect rising edge pulse
		58	data = ICR1; // get timer value after input capture
		59	SET_COUNTER_TO_ZERO;
		60	FALLING_EDGE_TRIGGER;
		61	if(data >= MIN_SYNC_TIME && data <= MAX_SYNC_TIME) // valid sync trigger
		62	{
		63	SET_PPM_OUT_HIGH;
		64	ppm_state = stPPM_CHANNEL_DATA; // next state: get data
		65	channel_number = 0;
		66	}
		67	else // trigger but not a valid sync time
		68	{
		69	SET_PPM_OUT_LOW;
		70	ppm_state = stPPM_SYNC_WAIT; // next state: wait for next sync event
		71	}
		72	break;
		73
		74	case stPPM_SYNC_WAIT: // detect falling edge pulse
		75	SET_PPM_OUT_LOW; // not nessecery, output should already be low
		76	SET_COUNTER_TO_ZERO;
		77	SET_CAPTURE_COUNTER_TO_ZERO;
		78	RISING_EDGE_TRIGGER;
		79	ppm_state = stPPM_SYNC; // next state: try again for new sync
		80	break;
		81
		82	case stPPM_CHANNEL_START: // detect rising edge pulse
		83	SET_COUNTER_TO_ZERO;
		84	SET_PPM_OUT_HIGH;
		85	FALLING_EDGE_TRIGGER;
		86	channel_number++; // prepare for next MX16s channel clock
		87	if(channel_number>7) // all eight channels read
		88	{
		89	SET_COUNTER_TO_ZERO;
		90	SET_PPM_OUT_HIGH;
		91	SET_TIMER_TO_COMPA_CTC;
		92	DISABLE_INPUT_CAPTURE;
		93	ENABLE_OUTPUT_COMPARE;
		94	OCR1A = START_PULSE; // startpulse length 0.4ms
		95	TRIGGER_INPUT_COMPARE_INTERRUPT;
		96	ppm_state = stPPM_CHANNEL_9_DATA; // 9th. channel but now self created
		97	channel_number = 0;
		98	}
		99	else
		100	ppm_state = stPPM_CHANNEL_DATA;
		101	break;
		102
		103	case stPPM_CHANNEL_DATA: // detect falling edge pulse
		104	SET_COUNTER_TO_ZERO;
		105	SET_PPM_OUT_LOW;
		106	RISING_EDGE_TRIGGER;
		107	ppm_state = stPPM_CHANNEL_START; // wait for next channel rising edge pulse
		108	break;
		109
		110	default:
		111	SET_PPM_OUT_LOW; // not nessecery, output should already be low
		112	SET_COUNTER_TO_ZERO;
		113	SET_CAPTURE_COUNTER_TO_ZERO;
		114	RISING_EDGE_TRIGGER;
		115	ppm_state = stPPM_SYNC; // next state: try again for new sync
		116	break;
		117	}
		118	sei ();
		119	}
		120
		121	// timer1_compare_interrupt (void)
		122	// Mixing channel 9 data into ppm out, start input capture for frame synchronisation
		123	ISR (TIM1_COMPA_vect)
		124	{
		125	cli ();
		126	switch (ppm_state)
		127	{
		128	case stPPM_CHANNEL_9_DATA:
		129	SET_PPM_OUT_LOW;
		130	SET_COUNTER_TO_ZERO;
		131	if (PINA & (1 << CHANNEL_9)) // Channel 9 on/off
		132	OCR1A = PPM_PULSE_MAX - START_PULSE;
		133	else
		134	OCR1A = PPM_PULSE_MIN - START_PULSE;
		135	// set OCR1A between [PPM_PULSE_MIN-START_PULSE] and [PPM_PULSE_MAX-START_PULSE] for transmitting analog value
		136	ppm_state = stPPM_FINISH_PULSE; // next State
		137	break;
		138
		139	case stPPM_FINISH_PULSE: // create last pulse
		140	SET_PPM_OUT_HIGH;
		141	SET_COUNTER_TO_ZERO;
		142	OCR1A = START_PULSE; // startpulse length 0.4ms
		143	ppm_state = stPPM_FRAME_END; // next State
		144	break;
		145
		146	case stPPM_FRAME_END:
		147	default:
		148	SET_PPM_OUT_LOW;
		149	RISING_EDGE_TRIGGER;
		150	DISABLE_OUTPUT_COMPARE;
		151	ENABLE_INPUT_CAPTURE;
		152	SET_TIMER_TO_COMPA_CTC;
		153	SET_COUNTER_TO_ZERO;
		154	SET_COMPARE_COUNTER_TO_ZERO;
		155	SET_CAPTURE_COUNTER_TO_ZERO;
		156	ppm_state = stPPM_SYNC; // next State
		157	TRIGGER_INPUT_CAPTURE_INTERRUPT;
		158	break;
		159	}
		160	sei ();
		161	}
		162
		163	int main (void)
		164	{
		165	cli (); // disable interrupts
		166
		167	DDRA &= ~(1<<PPM_IN); // set Input Capture Pin as input
		168	PORTA \|= (1<<PPM_IN); // enable pullup
		169
		170	DDRB \|= (1<<PPM_OUT_PIN); // configure PPM_OUT pin as output
		171	SET_PPM_OUT_LOW; // set low
		172
		173	DDRA &= ~(1 << CHANNEL_9); // Channel 9 (Pin 10) input
		174	PORTA \|= (1 << CHANNEL_9); // enable pullup
		175
		176	TCCR1A = ((0<<WGM11)\|(0<<WGM10)); // CTC mode
		177	TCCR1B = ((0<<WGM13)\|(1<<WGM12)\|(0<<CS12)\|(1<<CS11)\|(0<<CS10)); // CTC mode for COMPA, prescaler 8 / 8MHz => [1.0us]
		178
		179	CLEAR_INPUT_CAPTURE_INTERRUPT_FLAG; // reset ICF flag
		180	SET_COUNTER_TO_ZERO;
		181	SET_COMPARE_COUNTER_TO_ZERO;
		182	ENABLE_INPUT_CAPTURE;
		183	DISABLE_OUTPUT_COMPARE;
		184	RISING_EDGE_TRIGGER;
		185
		186	sei (); // enable interrupts
		187
		188	while(1);
		189	}

Subversion Repositories Projects

(root)/RC-Expander/branches/MX16s_9Ch_V1.0/main.c - Rev 1396